Effects of CO2 Enrichment and Drought on Photosynthesis,Growth and Yield of an Old and a Modern Barley Cultivar |
| |
| Authors: | I Schmid J Franzaring M Müller N Brohon O C Calvo P Högy A Fangmeier |
| |
| Affiliation: | Institut für Landschafts‐ und Pflanzen?kologie, FG Pflanzen?kologie und ?kotoxikologie, Universit?t Hohenheim, Stuttgart, Germany |
| |
| Abstract: | Susceptibility of crops to drought may change under atmospheric CO2 enrichment. We tested the effects of CO2 enrichment and drought on the older malting barley cultivar Golden Promise (GP) and the recent variety Bambina (BA). Hypothesizing that CO2 enrichment mitigates the adverse effects of drought and that GP shows a stronger response to CO2 enrichment than BA, plants of both cultivars were grown in climate chambers. Optimal and reduced watering levels and two CO2 concentrations (380 and 550 ppm) were used to investigate photosynthetic parameters, growth and yield. In contrast to expectations, CO2 increased total plant biomass by 34 % in the modern cultivar while the growth stimulation was not significant in GP. As a reaction to drought, BA showed reduced biomass under elevated CO2, which was not seen in GP. Grain yield and harvest index (HI) were negatively influenced by drought and increased by CO2 enrichment. BA formed higher grain yield and had higher water‐use efficiency of grain yield and HI compared to GP. CO2 fertilization compensated for the negative effect of drought on grain yield and HI, especially in GP. Stomatal conductance proved to be the gas exchange parameter most sensitive to drought. Photosynthetic rate of BA showed more pronounced reaction to drought compared to GP. Overall, BA turned out to respond more intense to changes in water supply and CO2 enrichment than the older GP. |
| |
| Keywords: | allocation patterns malting barley net photosynthesis stomatal conductance water‐use efficiency |
|
|
